The objectives of this longitudinal study are: 1) to determine whether early periodontal lesions (attachment loss and horizontal bone loss) indicate a predisposition to chronic periodontitis, 2) to determine the relationship between the prevalence of various types of oral mucosal lesions and patterns of consumption of alcohol, cigarette and smokeless tobacco, 3) to determine the prevalence and causes of fractured anterior teeth, in an adolescent population. The baseline data on prevalence of caries and periodontal lesions has been collected, and progress is being made in the analysis of these data. The analysis of the data on consumption of alcohol, cigarette, and smokeless tobacco, among these adolescents showed that smokeless tobacco usage is a predominantly white male activity, and decreases after 15 years of age. Alcohol use and smoking, however, transcends all groups with increasing usage with increasing age. Analysis of data on traumatized anterior teeth showed that clinical evidence of injury was found in 24% of the children, whose injured teeth were distributed as follows: dentine involvement 73%, unrestored with discoloration 13%, restored 5%, endodontic therapy 2%, and lost teeth 7%. Although there was an overall agreement of 75% between anamnestic and clinical data, in those children with clinical evidence of injury only 45% had a self reported injury. Conversely, in those with self-reported injury only 47% showed confirming clinical evidence.